(
课件网) Unit 5 Unit 5 A delicate world Ecosystems To learn something about ecosystems and understand the importance of ecological balance and contribute to the protection of ecosystems To listen to the conversation and get the detailed information about what makes bee habitats dangerous To learn to express doubt and respond to doubt What makes the ecosystem balance Ecosystems Ecosystem means all the animals and plants in a particular area, and the way in which they are related to each other and to their environment. Producer…, primary consumers…, secondary consumers…, decomposers… Look at the diagram and answer the questions. Pay attention to the words and expressions in bold. v. 溶解 n. 养分、营养物 n. 真菌 5 1. What does the diagram show The diagram shows a food chain — the connection between the living things. 2. What are the relationships between the living things The living things are closely connected with each other by the food they eat. Secondary consumers prey on primary consumers, primary consumers feed on producers, and producers absorb light from the sun, and water and dissolved nutrients from the soil, which are provided by decomposers. Complete the passage with the correct form of the words and expressions in Activity 5. In a woodland ecosystem, trees and other plants are producers. They 1_____ water, and take in nutrients from the soil and energy from the sun. Insects are an example of a primary consumer. They 2_____ the producers to provide food for them, and are 3_____ by secondary consumers: small mammals and birds. absorb rely on fed on absorb, dissolve, nutrient, rely on, provide energy, feed on, prey on, break down, release 6 They 4_____ the primary consumers. Fungi and bacteria are decomposers. They 5_____ animal waste and the remains of living things. The chemicals these decomposers 6_____ fertilise the soil and give the plants the nutrients they need to grow. break down prey on release absorb, dissolve, nutrient, rely on, provide energy, feed on, prey on, break down, release One of the oldest species in the ecosystem, the honey bee has been in existence for millions of years. A honey bee can fly as fast as 24 kilometres per hour and its wings can beat 200 times per second. In just one journey to collect pollen and nectar, one single honey bee can pollinate as many as 50 to 100 flowers. Bees can provide honey to us. But how Watch the video. Listening tips Read the given sentences and guess what you may listen to in the conversation; Underline the key words in each sentence and pay attention to the words while listening; Write down the words in blanks while listening, and check your spelling. Listen to the conversation and choose the true statements. 1. Bees are very important to our food supply because they provide honey. 2. The bee population is declining. 3. Without bees, humans would die out. 4. All human crops depend on bees for pollination. 5. If bees became ... ...
